Parkin is a proteinencoded by the PARK2 gene.The precise function of this protein is unknown; however, the protein is a component of a multiprotein E3 ubiquitin ligase complex which in turn is part of the ubiquitin-proteasome system that mediates the targeting of substrate proteins for proteasomal degradation. Mutations in this gene are known to cause a familial form of Parkinson's disease known as autosomal recessive juvenile Parkinson disease.

PARK2 is the parkin gene that may cause a form of autosomal recessive juvenile Parkinson disease due to a mutation in the parkin protein. This form of genetic mutation may be one of the most common known genetic causes of early-onset Parkinson disease.